Add !important
into your code for the background-image line
background-image:url(https://www.malenebreytenbach.co.za/wp-content/uploads/2019/08/Pattern-01.jpg) !important;
Otherwise try placing that code further down in the source code as something is loading in the source code after your code that is causing the background to remain white.
Worked like a charm! Thanks Jarret.